Beyond labels: are Mexican beans safe to eat? Unveiling the presence of potentially toxic elements in commercial samples from Mexican supermarkets

Abstract

In Mexico, beans rank as the third most important crop in terms of the area planted. Each person is estimated to consume approximately 10 kg/per year of beans. The national bean production for 2024 is projected to reach 918 million metric tons. As part of this study, the levels of potentially toxic elements were determined in 30 bean samples from four varieties: pinto, black, Peruvian, and mayflower. The analysis utilized high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) to determine levels of cadmium (Cd) and lead (Pb), hydride generation graphite furnace atomic absorption spectrometry (HG-GF AAS) to measure arsenic (As) and antimony (Sb), and a direct mercury analyzer for mercury (Hg) detection. The limits of detection for As, Cd, Hg, Pb, and Sb were 2.74, 1.52, 0.131, 15.9 y 2.98 µg/kg, respectively. Concentrations (µg/kg) ranged from 11.1 to 164 for As, 5.12 to 44.7 for Cd, 0.560 to 3.74 for Hg, 105 to 202 for Pb, and 13.1–51.3 for Sb. While non-cancer risks were considered negligible for both adults and children, significant cancer risks were identified in certain samples for adults. These findings emphasize the critical need for ongoing monitoring and regulatory measures to ensure food safety, especially regarding potentially toxic elements. They also highlight the necessity for continued research to protect public health.

Graphical abstract